I am not getting the tire frying torque and seat of the pants acelleration I was expecting. Please help. Here is my combo. 69 chevelle 4spd 454+30 with .100 dome hyper pistons, complete XE 274 cam kit, set of 215 closed chamber heads machined for the larger 2.19 valves with 104CC chambers, a GM 375HP 163 aluminum intake with 750 holly dp and points ignition, exhaust manifolds with flowmasters and 3.08 gears. My understanding from reading the posts on this site was that this combo would put out plenty of power. Am I doing something wrong?

oops.

what is your timing set at? You can't tell me that it won't fry the tires :confused: Big blocks definately need headers also 1.75"/3" dynomax coated headers is just what the doctor ordered graemlins/thumbsup.gif

Timing is 36 degrees total all in by 3000 rpms. The car will turn the tires pretty good, and has decent acceleration, but just doesn't seem like i'm getting what I paid for. Headers are coming soon. I was expecting the pinned to the seat acceleration, and for it to be pretty scarry, maybe I am just being to hopefull.

I'd lay money that headers will be what wakes it up with that cam,compression,intake and carb...all the rest is letting it breathe,but stock manifolds will not.

Should I elect for the 3.73 gears in addition to the headers?

I would go to 3.73's if you don't plan on any long hauls...tough on mileage,but as an all around performance/street gear, I like em graemlins/thumbsup.gif If mine ever give up,I'll go 4.11's. I've got a 15 mile drive to the big town of Springfield and it spends more time at the track here lately,this time of year anyway.

Something is amiss. Very simular to my engine, I did have 3.08 gear in the 10 bolt prior to swapping for the 9", 3.70 gear currently in use. Even with the 3.08 gear it would light up the hides at will in 2nd gear from a 30mph roll. My ride scares the willeys out of normal folks, and will impress most. That combo should be worth around 500 hp and torque with some good CHEAP dynomax 1 3/4 x 3 headers. I would think that with the 4 speed trans that thing would be a beast on the street............What kind of performance were you looking for???? That thing will go 12's with your current gear IF you can hook and launch. graemlins/thumbsup.gif

I notice that you have points ignition. I don't think that a swap to an HEI would "wake" the combo up like headers will, but it would be a nice, relatively cheap upgrade.

What size exhaust do you currently have?

In order, my suggestions would be:

1. 1 3/4" headers

2. HEI ignition with a curve kit.

3. Holley pump cam kit with a selection of squirters, jets and power valves.

Tune the heck out of what you have and then gear it deeper depending on your usage.

I run basically the same combo,but with 2.06/1.72 valves and the UD 280/288 (same pistons/heads)
ET and gear ratio in signature
It will do silly burnouts..with 2.73's at any speed up to about 35 MPH :D
When changing from manifolds to headers and a full 2.5" exhaust with no other changes,I picked up over 6 MPH and over a half second (13.7 to a 13.2) in the 1/4.
The 6 MPH is close to 60 HP I'm sure.
Something to think about.
Are you sure you have wide open throttle?
Your timing is fine,thats about where mines at..18* base,36-38* total by 2800-3000

What 4-speed? M20 or M21/22?

A 3.08 with an M21/22 isn't a good combo.

It's an M-20. When you say not a good combo are you referring to strength or just gearing. What is your reccomendation?

As for something being amis what would this be? the engine seems to run very smooth and sounds mean.

It has 2 1/4" exhaust running out of exhaust manifolds through flowmasters all the way out the back. The throttle is opening all the way.

I want it to be strong enough to hold you down in the seat upon acceleration. It seems to have good throttle response like its tuned pretty well, but just doesn't have what I would expect from a big block car. I mean I have been in 5.0 mustangs that were fairly stock that I was more impressed with. I appreciate the feedback, maybe I will get somewhere with the suggestions.

Start with the headers, confirm timimg around 38 total all in by 3000. (have you checked tdc and what your pointer is telling you?) That thing should eat 'Stangs alive and be spittin out knawed up horse bones. :cool:

Please expound on the question regarding checking TDC. I degreed the cam upon installation and it seemed fine.

Originally posted by 69SS4spd:
Please expound on the question regarding checking TDC. I degreed the cam upon installation and it seemed fine. With piston #1 at TDC your timing pointer (where you use your timing light) should read 0.

Rod

In refering to TDC........ Insure that the motor has the #1 piston at TDC and that the pointer on the balancer is indicating "0" on this cylinders compression stroke. You can use a piston stop in the spark plug hole, with all plugs removed turn the engine over by hand, note the position / degree marking on the balancer when the piston comes up agaist the stop, turn the motor over by hand again in the oppisite direction and note where it comes to a stop. TDC is directly in the middle of the two locations on the balancer where the motor / #1 piston came up against the piston stop. Adjust your pointer to reflect the "known Zero" on the balancer. Adjust timing with your "new known zero indication" to around 38 degrees total with any vac advance disconnected / vacume source plugged. Hook up the old timing light, rev the engine. the timing should advance to around 38 degrees, and then stop advancing around 3000 rpm.

Cam is too big for the gears and the restricted exhaust.

If fairly stock 5.0 'stangs impressed you more than that combo, something must be terribly wrong! Snatch you some headers somewhere, hopefully that will cure the problem.

a 2.25" exhaust with manifolds is NOT going to cut it.Your choking that motor.As I mentioned,60 HP and half second in the quarter was my gain going to headers/2.5" exhaust.Your M20 is fine,but 3.73 gears would also be quite beneficial.Don't go by seat of the pants either.

ASSUMING 15cc on those .110" domes ( ???) your static is 10.45 ( also assuming the pistons are .015" down in the hole).

If you have the XE274 in there straight up, dynamic is 8.25. If you put in in +4 like you should have dynamic becomes 8.6. Too high with iron ( heck it almsot too high with my old GM alums).

So to say the cam is too big is way off base. If Bill menat vis-a-vis the 3.08s, well maybe. Remember with a stick car you have NO TORQUE MULTIPLICATION off the line, i.e., no torque converter. Its all gear.

I appreciate everyone's reply. The piston are 13.8 cc domes and the Cam is at 106 degrees ICL. With the 104 cc chambers the DCR I calculated was 8.25. I am not experiencing any detonation that I am aware of, and the car runs smooth, just not fast enough. How can I rule out detonation?

Could the Maniforld choice be the issue?

Sounds like the answer is in the exhaust and or gearing? Could transmission problems be the culprit?

I'm thinking about a track visit to see where I am. I would expect to be deep into 8's in an 1/8 with the combo. What modifications would be required for the 7's

1.75" headers and 3" pipes with dumps or out the back. Its gotta breathe!!

Intake is fine,change the exhaust.Like I said,headers and a 2.5" exhaust will probably net you 50-60 real HP (I gained 6 MPH)
I ran an 8.25 1/8 mile with my car w/ 2.73's/TH400 and I have small valves,but the same pistons/heads.
low 8's with 3.08's might not happen..w/3.55's or 3.73's it might,and just because of the 4 speed.

Originally posted by 69SS4spd:
It's an M-20. When you say not a good combo are you referring to strength or just gearing. What is your reccomendation? I was referring to the gear ratios. The M20 has a 2.52 first gear. The M21/22 only has a 2.20 first gear ratio. The strength of a M22 is better, but the gearing of a M20 is better if you only have 3.08 rear gears.

Thanks to everyone for your replies. The plan is to check everything out regarding timing and potential detonation and add the 1 3/4 headers and 2 1/2 mandrel bent exhaust, electronic ignition, 3.73 gears, tune the carb and let' er rip. Any other suggestions are welcomed.

Has anyone had any clearance problems with the dynomax ceramicoated headers referred to in this post with a 69 chevelle, big block and 4 spd?

Try and get your distributor recurved.

Originally posted by 69SS4spd:
Has anyone had any clearance problems with the dynomax ceramicoated headers referred to in this post with a 69 chevelle, big block and 4 spd? I used them on my 70, I did have to put a little ding on the drivers side to clear the brake valve on the frame. A very small one and it didnt hurt the coating. I'm happy with them.
Ron